U.S. Pat. No. 7,427,872 (Patent Document 1) and U.S. Pat. No. 8,212,587 (Patent Document 2) disclose inventions of transmitters and receivers that are capable of performing signal transmission conforming to the Universal Serial Bus (USB) 3.1 standard. The transmitters described in these documents are devices that transmit differential signals to a receiver via differential signal lines having AC coupling capacitors provided in the middle thereof, and have an RX-Detect function that detects whether the receiver is connected to the differential signal lines in a receivable state.